|  | 6.2 | ACL Configuration Tasks
| 6.2.4 | The host command

A second common condition where Cisco IOS permits an abbreviation in the ACL wildcard mask is when you want to match all the bits of an entire IP host address. For example, say you want to specify that a specific IP host address will be permitted in an ACL test. To indicate a host IP address, you would enter the full address (for example, 172.30.16.29); then, to indicate that the ACL should check all the bits in the address, the corresponding wildcard mask bits for this address would be all zeros (that is, 0.0.0.0). You can use the abbreviation host to communicate this same test condition to Cisco IOS ACL software. In the example, instead of typing 172.30.16.29 0.0.0.0, you can use the word host in front of the address. For example, instead of using this: Router(config)# access-list 1 permit 172.30.16.29 0.0.0.0 you can use this: Router(config)# access-list 1 permit host 172.30.16.29